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                                                                     Exhibit 5.1







                                                                  April 19, 2001




The Goldman Sachs Group, Inc.,
    85 Broad Street,
        New York, New York 10004.

Ladies and Gentlemen:

        In connection with the registration under the Securities Act of 1933
(the "Act") of 4,032,513 shares (the "Securities") of common stock, par value
$0.01 per share, of The Goldman Sachs Group, Inc., a Delaware corporation
(the "Company"), and 4,032,513 associated stock purchase rights (the "Rights")
issued pursuant to the Stockholder Protection Rights Agreement, dated as of
April 5, 1999 (the "Rights Agreement"), between the Company and ChaseMellon
Shareholder Services L.L.C., the predecessor of Mellon Investor Services LLC, as
Rights Agent (the "Rights Agent"), we, as your counsel, have examined such
corporate and partnership records, certificates and other documents, and such
questions of Delaware law, as we have considered necessary or appropriate for
the purposes of this opinion. Upon the
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basis of such examination, we advise you that, in our opinion:

        (1) The Securities have been validly issued and are fully paid and
nonassessable.

        (2) Assuming that the Rights Agreement has been duly authorized,
executed and delivered by the Rights Agent, the Rights associated with the
Securities have been validly issued.

        In connection with our opinion set forth in paragraph (2) above, we note
that the question whether the Board of Directors of the Company might be
required to redeem the Rights at some future time will depend upon the facts and
circumstances existing at that time and, accordingly, is beyond the scope of
such opinion.

        The foregoing opinion is limited to the laws of the State of Delaware,
and we are expressing no opinion as to the effect of the laws of any other
jurisdiction.

        We have relied as to certain matters on information obtained from public
officials, officers of the Company and the general partner of the Company's
predecessor, The
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Goldman Sachs Group, L.P., and other sources believed by us to be responsible.

        We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement relating to the Securities and the Rights and to the
reference to us under the heading "Validity of Common Stock" in the Prospectus
included therein. In giving such consent, we do not thereby admit that we are
in the category of persons whose consent is required under Section 7 of the Act.

                                                     Very truly yours,

                                                    /s/ SULLIVAN & CROMWELL